Dempster, South Dakota Weather Forecast Discussion

908
FXUS63 KABR 092016
AFDABR
Area Forecast Discussion
National Weather Service Aberdeen SD
316 PM CDT Tue Sep 9 2025
.KEY MESSAGES...
- Mainly elevated smoke will remain across the area tonight,
  while slowly improving Wednesday. This will create a milky sky,
  with reductions in surface visibility no longer expected.
- Morning fog will be potentially dense over portions of eastern
  SD and west central MN late overnight into Wednesday morning.
- There is a Marginal Risk (level 1 out of 5) of severe weather
  over portions of north central SD late Thursday afternoon into
  Thursday evening. Additional strong to potentially severe storms
  will be possible this weekend.
&&
.DISCUSSION...
Issued at 316 PM CDT Tue Sep 9 2025
The latest surface weather map showed a weak surface pattern
overhead, with a trough stretching from eastern CO through
southwestern SD and northeastern SD. Winds around around 10mph or
less across the forecast area. The smoke that has been overhead over
the last couple of days will diminish in coverage as we move into
Wednesday. The increased cloud cover we have put in as a result of
the smoke will end Wednesday evening. Taking a look at the latest
surface observations, smoke is not reducing visibilities at any of
the AWOS/ASOS weather stations near our area. Any mention of patch
or areas of smoke will stay out of the forecast.
Fog will be the main weather concern late tonight into Wednesday
morning. The EC ensemble meteograms have been highlighting this
period for the last several days, with a 70% chance of visibility at
8D3/Sisseton below 0.2 miles, 50% at ATY/Watertown, and 25% chance
at ABR/Aberdeen. For comparison, the probability was 40% at ABR this
morning when we got down to 1/4 miles. The potential for fog tonight
has been added to the HWO and will be highlighted via social media.
Fog headlines may be needed later tonight into Wednesday morning for
portions of eastern SD and west central MN.
At least a couple of CAMs do highlight the potential for shower
activity across portions of central (and mainly north central) SD
this evening. Another area of concern is south central SD overnight
(06-13Z). The coverage area is very small, and confidence remains
low on any showers developing. As a result, the dry weather forecast
will continue.
For Wednesday night we`ll be monitoring for the potential for
showers/storms to develop over eastern MT/western ND to near our
area. Timing wise, it looks like precipitation may clip our north
central SD counties by daybreak, but again the potential remains low.
There is a Marginal Risk (level 1 out of 5) of severe weather over
portions of north central SD late Thursday afternoon into Thursday
evening. A lee trough stretching from MT through WY/far southwestern
SD and CO will be the focus for potential storm development. We`ll
need to watch if storms are able to develop upstream over western SD
and move northeast into our area.
The trough will push a low over western to central SD and NE during
the day Friday. It will remain over the forecast area through the
weekend. This will be while the 500mb low moving onshore over OR/CA
this afternoon edge east across MT/ID/UT Friday, with southwest flow
returning aloft. At this point the low looks to consolidate with an
additional low moving onto the west coast, with a trough remaining
over the Northern Plains into next week. Additional strong to
potentially severe storms will be possible this weekend as the
initial 500mb wave moves in. The highest chances of precipitation
over the next week is Saturday through the day Sunday at 30-60%.
&&
.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1223 PM CDT Tue Sep 9 2025
Terminals KABR,KATY,KPIR,KMBG
IFR ceilings KATY and KABR will likely stick around for a little bit
longer, probably an hour or so, before dissipating. Then VFR
ceilings will stay over the terminals until late tonight, when more
fog is forecast to develop. This will mainly affect KATY and drop
visibilities and ceilings at times to IFR and LIFR categories.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
DISCUSSION...06
AVIATION...12

NWS ABR Office Area Forecast Discussion